In the final assembly of an oil or gas producing well, the production tubing is generally provided with a subsurface safety valve located a distance below the wellhead assembly. Thus, there is necessity and/or requirement to provide an independent fluid pressure passage through the wellhead equipment, i.e., tubing head bonnet and tubing hanger, to allow manipulation of the subsurface valve. Small bore tubing is connected to the passageway provided between the bonnet and hanger and down to the safety valve to be actuated. Passages through the bonnet and hanger are precisely drilled and must be aligned as the parts are brought together. If alignment at their mating surfaces is not achieved, reorientation for proper alignment is difficult and expensive.
Fluid pressure passageways may be provided by other means. For example, inward through a tubing head outlet, through the tubing hanger, and down the control line to the safety valve. Again, proper alignment between the hanger and outlet must be accomplished or fluid pressure injection problems are encountered.
A structure is needed that will eliminate the problem of alignment and that will provide passageways that are sealed in a metal-to-metal configuration. However, the problem solved by the invention extends beyond the oil well art.